There exists a general need in wireless communications devices for certain integrated circuit (IC) packages to be isolated from electromagnetic interference (EMI) in order to maintain proper device performance. The electromagnetic interference may be received from, or transmitted to, the environment.
One approach for shielding an IC package from electromagnetic interference is to cover the IC package with a grounded metal enclosure typically called a can. However, this approach may be costly and lacks design flexibility. In addition, the metal can adds weight and adds significant size to the IC package footprint.
Another approach is to use a physical vapor deposition (PVD) process that deposits in a vacuum chamber a conductive layer on an upper surface of the IC package. Sputtering is a type of PVD that involves ejecting material from a target that is a source onto a substrate (such as an IC package) in a vacuum chamber. However, this approach is expensive and it is difficult to control a thickness of the coating layer. Consequently, there is a need for electrically shielding an IC package in a relatively straightforward manner.